Is my bento box microwave-safe?

I've run through the "What's your box topic" and I don't think this has been mentioned before.

My bento box [1] had just arrived yesterday and I'd like to know if it's microwavable. It's bottom says that it's made of some synthetic plactic (which I don't know how to spell) and is able to withstand temperatures from -20 to 120'C. Would I be able to put it in the microwave (lids removed)? And also, for how many minutes?